The present disclosure relates generally to an arrangement for, and a method of, enhancing the accuracy of data collection for multiple items located in an indoor venue, such as a retail store, a factory, a warehouse, or a like indoor controlled area.
Radio frequency (RF) identification (RFID) reading technology and bar code reading technology are both employed for logistics concerns, material handling and inventory management in retail stores, factories, warehouses, distribution centers, buildings, and like indoor venues or controlled areas. A known RFID system includes a handheld RFID reader or mobile data capture device for interrogating at least one RFID tag, and preferably multiple RFID tags, in its coverage range. Each RFID tag is usually attached to, or associated with, an individual item, or to a package for the item, or to a pallet or container for multiple items. The RFID reader receives an RF signal from the tag(s) and decodes the signal into data. The decoded data, also known as a payload or information data, can denote a serial number, a price, a date, a destination, other attribute(s), or any combination of attributes, and so on, for the tagged item. A known bar code reading system includes a handheld reader or mobile data capture device, for example, either a moving laser beam-based reader or a solid-state imager-based reader, for electro-optically reading a bar code symbol that is associated with an item or a group of items. The symbol may be one-dimensional, such as a Universal Product Code (UPC) symbol, or a two-dimensional matrix code, such as a Quick Response (QR) code. The symbol may be printed on a label affixed to, or adjacent, the item(s). The bar code reader decodes return light from the symbol into information data, such as an item identifier, or a reference to a Uniform Resource Locator (URL), or any type of data related to the item.
In some applications, it is desirable to associate the information data captured by either of the above-described types of mobile devices with the location of the item in a venue. For example, when inventorying a population of items in a venue, a complete inventory should include not only the identity of each item, but also the location of each item in the venue. As another example, in an order fulfillment application, also known as voice-directed picking, workers or operators of the mobile devices are often paid by the rate at which an order for one or more items is filled, thereby sometimes leading some workers to rush and perhaps pick the wrong items. Knowing the location of a mobile device held and operated by a worker to capture data from each item and, in turn, the position of the worker in the venue is used to verify that the worker is in the correct position when a particular item is being picked. Such position verification can be used to train workers to not pick the wrong items and to improve the success of the picking task.
It is known to deploy a real-time locationing system in the venue to determine the location of the mobile device and, in turn, the location of the items in a reading or coverage zone in the vicinity of the mobile device. The locationing system may employ RF signals, or optical (usually infrared) signals, or acoustic (usually ultrasound) signals to locate the mobile device. For example, one or more ultrasonic emitters can be operated to determine the location of a mobile device that contains an ultrasonic receiver. Each ultrasonic emitter transmits ultrasonic energy, preferably in a short burst, which is received by an ultrasonic transducer (e.g., a microphone) in the ultrasonic receiver, thereby establishing the presence and the specific location of the mobile device within the venue, typically by using triangulation techniques known in the art.
Yet, the performance of the known locationing systems is sometimes less than ideal. RF, optical and acoustic locationing systems are all subject to multi-path reflections and scattering of their respective signals off various reflecting and/or absorbing surfaces, such as walls, curtains, windows, shelves, equipment, etc., in the venue, and sometimes their respective signals are weak, or even blocked by such surfaces. For example, optical and acoustic signals do not pass through walls. An RF system may also be subject to interference from stray RF signals. An optical system may also be subject to interference from ambient bright light. An acoustic system may also be subject to interference from ambient loud noise. Moreover, locationing performance may suffer when the mobile device is being moved quickly, for example, when held and operated by an operator running through the venue, rather than being held momentarily steady by the operator during data capture. During these less than ideal conditions, known locationing systems typically report an erroneous location, or perhaps the last known location, of the mobile device. Determining the locations of the items based on these erroneous locations of the mobile device results in erroneous item locations. Associating the erroneous item locations with the information data captured from the items results in an inaccurate inventory record.
Accordingly, it would be desirable to take such less than ideal performance by the locationing system into account, to alert an operator of the mobile device to take corrective action when the performance by the locationing system is below a reference threshold, and to prevent data capture when the performance by the locationing system is below a reference threshold, all with the goal of more accurately determining the locations of the items so that an accurate inventory record can be obtained.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions and locations of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of embodiments of the present invention.
The arrangement and method components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.